Rotating-cam vane pump



Feb. 14, 1967 Filed June 26, 1964 R. A. MCCRAY ROTATING-CAM VANE PUMP 4 Sheets-Sheet 1 Feb. 14, 1967 R. A. MCCRAY 3,363,790

ROTAT ING CAM VANE PUMP Filed June 26, 1964 4 Sheets-Sheet :5

INVE/vroe,

Feb. 14, 1967 R. A. MGCRAY ROTATING-CAM VANE PUMP 4 Sheecs-Sheet 4 f 2&2 t?

United States Patent C) 3,303,790 ROTATING-CAM VANE PUMP Richard A. McCray, Los Angeles, Calif., assignor, by mesne assignments, to International Telephone and Telegraph Corporation, a corporation of Maryland Filed June 26, 1964, Ser. No. 378,150 7 Claims. (Cl. 103-117) The present invention relates in general to a rotary pump of this vane type and, more particularly, to a pump of this type wherein the vanes are ca-rried by the housing of the pump and extend radially inwardly into the lpumping chamber, and wherein the volumes of the intervane spaces are alternately increased and decreased by a rotating cam in engagement with the inner ends of the vanes.

Still more particularly, a rotating-cam vane pump of the foregoing type includes: ya housingr provided therein with a cylindrical pumping chamber; `a cam in and rotatable about the axis of the pumping chamber and having axially spaced end Walls and a peripheral wall defining one or more lobes; a shaft rotatable relative to the housing about the axis of the pumping chamber and connected to the cam to rotate same; and circumferentially spaced, displaceable vanes carried by the housing and extending radially inwardly into the pumping chamber :and into engagement with the .peripheral wall of the cam. With this construction, the cam alternately increase and decreases ythe volumes lof the spaces between the vanes one or more times p-er revolution so as to provide the pumping action characteristic of a pump of this type.

It is conventional in such a -pump to utilize the cam itself as an inlet valve means for delivering the iluid to be pumped to the inte-rvane spaces as the volumes there-A of are increased. This is accomplished by forming in the cam an inlet passage means having lan inlet end in at least one of the end walls of the cam, and having at least one outlet end in the peripheral wall of the cam at a circumferential ylocation such that it always communicates with intervane spaces of increasing volume as the'.

cam rotates. Preferably, each inlet end of the inlet passage means is centrally located on the axis of rotation of the cam, Vand the inlet passage means may be so shaped that it provides a centrifugal pumping action as the cam rotates. With this construction, any tendency toward cavitation is minimized and the tluid being pumped is delivered to the increasing-volume intervane spaces under pressure to insure maximum lling thereof. Further, since 4the vanes do not rotate, the Huid in the intervane spaces does not rotate, which tends to minimize cavit-ation even more.

The primary object of the invention is to provide a rotating-cam vane pump of the foregoing construction including an outlet valve means, for discharging t-he fluid being pumped from the decreasing-volume intervane spaces, comprising at least one outlet valve plate rotatable with the cam and provided radially outwardly of the peripheral wall of the cam with at least one outlet opening so ylocated circumferentially that it constantly communicates with intervane spaces of decreasing volume.

Another object is to provide a cam having at least one outlet valve plate Aconstituting a radially outward extension of one end of the cam, and preferably a cam end in which `an axial inlet end of the inlet passage means is formed.

Still another object is to utilize the outlet valve plate or plates as a means for closing an open end or ends of the cylindrical pumping chamber, the periphery of ice each outlet v-alve plate cooperating with the housing in a Huid tight manner to achieve this result.

A further object of the invention is to provide a pump having in the housing at least one axial inlet port which communicates with an adjacent axial inlet end of the inlet passage means in cam, and having in the housing at least one annular outlet passage means which communicates with the outlet opening or openings in an adjacent outlet valve plate and which encircles an adjacent axial inlet port in the housing, such annular outlet passage means being located on the opposite side of the adjacent outlet valve plate from the pum-ping chamber.

Yet another object of the invention is to provide a housing which includes an open-end body portion having the open-end pumping chamber therein, and which includes at least one end closure portion having therein an axial inlet port and a surrounding annular outlet passage, means, and also having therein an outlet port in communication with the annular outlet passage means.

As suggested by -the foregoing, the fluid being pumped may be taken into the cam at one or both ends of the cam, and may Ebe discharged from the pumping chamber at one or both ends of the pumping chamber. Providing the inlet passage means with axial inlet ends at both ends of the cam, and providing Outlet valve plates at both ends of the cam, respectively result in improved inow of the fluid being pumped into the increasingvolume intervane spaces, an improved outflow of pumped fluid from the decreasing-Volume intervane spaces, thereby permitting higher rotational speeds for the cam.

The foregoing objects of the present invention, together with various other objects thereof which will be evident to those skilled in the pump art in the light of this disclosure, may be achieved with the exemplary embodiments of the invention described in detail hereinafter and illustrated in the accompanying drawings, in which:

FIG. l is a perspective view of a rotating-cam vane pump wnich embodies the invention, with parts of the y housing of the pump broken away to reveal the interior of the pump;

FIG. 2 is an enlarged, longitudinal sectional View containing the axis of the pump of FIG. l;

FIGS. 3 and 4 are transverse sectional views both taken along the arrowed line 3 3 of FIG. 2, but illustrating diierent operating positions of various components of the Pump;

FIG. 5 is a longitudinal sectional view of another rotating-cam vane pump which embodies the invention, FIG. 5 being taken along the arrowed line 5 5 of FIG. 6;

FIG. 6 is a transverse sectional View taken along the arrowed line 6 6 of FIG. 5; and

FIG. 7 is a semidiagrammatic longitudinal sectional view of still another rotating-cam vane pump which embodies the invention.

PUMP 10 Referring particularly to FIGS. l and 2 of the drawings, the embodiment of the invention illustrated therein is designated generally by the numeral 10 and is shown as including a housing 12 carried by a suitable mounting pedestal 14. The housing 12 is formed in two parts, viz., a body portion 16 open at one end, and a closure portion 18 for closing the open end of the body portion. 'Ihe two parts of the housing 12 may be secured together in any suitable manner, no securing means being shown.

The body portion 16 of the housing 12 is provided therein with a cylindrical pumping chamber 20 having an open end 22, the other end of the pumping chamber being shown as closed by an end wall 24 of the body portion of the housing. Coaxial with the pumping chamber 20, and extending thereinto through the end wall Y24,V is a shaft 26 mounted for rotation in a suitably sealed bearing 28 carried by the mounting pedestal 14. The shaft 26 is sealed relative to the end wall 24 of the pumping chamber 20 by a suitable sealing assembly 30 interposed therebetween.

The shaft 26, which may be driven in any suitable manner, drives a cam 32 disposed in and rotatable about the axis of the pumping chamber 20. The cam 32 is suitably connected to the shaft 26 for rotation therewith. In the particular construction illustrated, the cam 32 is seated against an annular shoulder 34 on the shaft 26 by a nut 36 acting on the cam through a washer 38. A key 40 provides a torque transmitting connection between the shaft 26 and the cam 32.

The cam 32 includes end Walls 42 and 44 and a peripheral wall 46 spaced from the peripheral wall of the pumping chamber 20, the end wall 42 abutting the end wall 24 of the pumping chamber. The open end 22 of the pumping chamber 20 is closed by an annular flange 48 on the cam 32. The annular flange 48, which is shown as formed integrally with the cam 32, extends radially outwardly beyond the peripheral wall 46 of the cam, and one side of the annular flange forms a radially outward extension of the end wall 44 of the cam. The periphery of the annular flange 48 is disposed in an annular groove 50 in the housing 12, such groove being formed in part by the body portion 16 of the housing and in part by the closure portion 18 thereof.

Referring particularly to FIGS. 3 and 4 of the drawings, circumferentially spaced, displaceable vanes 52 are carried by the body portion 16 of the housing 12 and extend inwardly into the pumping chamber 20 and into eugagement with the peripheral wall 46 of the cam 32. Any suitable displaceable vanes may be utilized. In the particular construction illustrated, flexible, elastomeric vanes 52 are employed, the outer ends of such vanes being inserted into longitudinal grooves 54 in the peripheral wall of the pumping chamber 20. The longitudinal grooves 54 and the outer ends of the vanes 52 are so formed as to key the vanes in the grooves.

The cam 32 is shown as provided with a single lobe 56 which alternately increases and decreases the volumes of the spaces 58 between the vanes 52, as the cam rotates, to provide the pumping action characteristic of a pump of this type. With the single lobe 56 shown, the volume of each intervane space 58 is alternately increased and decreased once during each cam revolution. However, it will be understood that two or more pumping cycles per cam revolution may be achieved through the use of a cam having two or more lobes.

The cam 32 acts as an inlet valve means for delivering the iluid to be pumped to the intervane spaces 58 as the volumes thereof are increased in response to cam rotation. More particularly, the cam 32 is provided therein with inlet passage means 60 having an axial inlet and end 62 formed in the end wall 44 of the cam and centrally located on the axis of rotation thereof. The inlet passage means 60 includes a cylindrical central portion 64 one end of which defines the axial inlet end 62 of such passage means. From the cylindrical central portion 64 thereof, the inlet passage means 60 spirals outwardly to an outlet end 66 in the peripheral wall 46 of the cam 32, such outlet end being bifurcated by a radial partition 68 to prevent damage to the vanes 52 by the edges of the outlet end of the inlet passage means.

The outlet end 66 of the inlet passage means 60 is so located circumferentially of the peripheral wall 46 of the cam 32 that it delivers the lluid to be pumped to those intervane spaces 58 the volumes of which are being increased as the cam rotates in the direction of the arrow 70. This action will be apparent from a comparison of FIGS. 3 and 4 of the drawings. A portion 72 of the inlet passage means 60 adjacent the outlet end 66 thereof is separated from the cylindrical central portion 64 of the inlet passage means by a partition 74 extending circumferential-ly in the direction of rotation. This construction provides the inlet passage means 60 with a centrifugal pumping action in response to rotation of the cam 32 in the direction indicated. This centrifugal pumping action is important since it delivers the fluid being pumped to the increasing-volume intervane spaces 58 under pressure to insure maximum filling thereof. Also, the utilization of the axial inlet provided by the axial inlet end 62 of the inlet passage means 60, and the cylindrical central portion 64 thereof, minimizes any tendency toward cavitation.

The uid to be pumped is introduced into the axial inlet end 62 of the inlet passage means 60 through an axial inlet port 76 formed in the closure portion 18 of the housing 12. The closure portion 18 and the end wall 44 of the c-am 32 are formed to provide a labyrinth seal 78 encircling the axial inlet end 62 `of the inlet passage means 60` and the axial inlet port 76. However, it will be understood that other types of seals may be employed.

An important feature of the invention is that the annular ange 48, in addition to performing the function of closing the open end 22 of the pumping chamber 20, lalso serves as an outlet valve means for receiving the pumped fluid from those intervane spaces 58 the volumes of which are being decreased by the cam 32. More par- Y ticularly, the annular l'flange 48 may be regarded as constituting an outlet valve plate, and it is provided, between the peripheral wall 46 of the cam 32 and the peripheral wall of the pumping chamber, with -a circumferentially extending outlet opening 80 so located circumferentially `as to be in communication with the decreasing-volume intervane spaces. This action will be apparent from a comparison of FIGS. 3 and 4 of the drawings.

The outlet yopening 80 in the outlet valve plate 48 is in constant communication with an annular outlet passage means 82 formed in the closure portion 18 of the housing 12 and leading -to an outlet port 84 formed therein. The outlet passage means 82, which is located on the opposite side of the outlet valve plate 48 from the pumping chamber 20, encircles the axial inlet port 76 and is sealed with respect thereto by the laby-rinth seal 78. The outer periphery of the outlet passage means 82 is sealed by a simil-ar labyrinth seal y86, or other suitable seal. The particular construction illustrated provides a convenient porting arrangement wherein both the inlet port 76 and the outlet port 84 are accessible from the same end of the pump 10.

PUMP

Turning to FIGS. 5 and 6 of the drawings, the embodiment of the invention illustrated -therein is designated generally by the numeral 110 and is shown as including a housing 112 bolted, or otherwise secured, to a suitable mounting pedestal 114. The housing 112 is formed in three parts, viz., a tubular lbody portion 116, an end mounting portion 117 closing one end of the body portion 116 and secured to the pedestal 114, and an end closure portion 118 closing the other end of the body portion. The three parts lof the housing 112 may be bolted together as shown, or secured together in any other sui-table manner.

The tubular body portion 116 of the housing 112 is provided therein with a cylindrical pumping chamber 120 having an open end 122, the `other end of the pumping chamber being shown as closed by the end portion 117 of the housing. Coaxial with the pumping chamber 120, and extending thereinto through the end portion 117 of the housing 112, is a shaft 126 mounted for 4rotation in a suitably sealed bearing 128 carried by the mounting pedestal 114. The shaft 126 is sealed relative to the end portion 117 of the housing 112 by a suitable sealing asf sembly 130 interposed therebetween.

The shaft 126, which may be driven in any suitable manner, drives a cam 132 disposed in and rotatable about the axis of the pumping chamber 120. The cam 32 is suitably connected Ito the shaft 126 for rotation therewith. In the particular construction illustrated, the cam 132 has an annular surface seated against an annular shoulder 134 on the shaft 126 by a -nut 136 acting on the cam through a washer 138. A `key 140 provides a 4torque transmitting connection between the shaft 126 and the cam 132.

The cam 132 includes end walls 142 and 144 yand a peripheral wall 146 spaced from the Iperipheral Wall of the pumping chamber 120, the end wall 142 abutting the end portion 117 of the housing 112. The open end 112 of the .pumping chamber 120 is closed by an Iannular flange 148 on the cam 132. The annular ange 148, which is shown as formed integrally with the cam 132, extends radially outwardly beyond the peripheral wall 146 of the cam, and one side of the annular liange forms a radially outward extension of the end wall 144 of the cam. The periphery of the annular ange 148 is disposed in an annular groove 150 in the end portion 118 of the housing 112.

As best shown in FIG. 6 of the drawings, circumferentially spaced, displaceable vanes 152 are carried by the tubular body portion 116 of the housing 112 and extend inwardly into the pumping chamber 120 and into engagement with the peripheral wall 146 of the cam 132. In the preferred construction of the invention, the vanes 152 are elastomeric and are formed integrally with an elastomeric annulus 154 carried by, and preferably bonded to, the tubular body .portion 116 ofthe housing 112. The elastomeric annulus 154 has considerable thickness in the radial direction so that, as the vanes 152 flex, adjacent portions of the elastomeric annulus 154 flex with them. With this construction, stresses developed at the roots of the vanes 152 are distributed throughout the adjacent portions of the annulus 154, thereby avoiding stress concentrations tending to result in cracking of the vanes adj-acent their roots, which is an important feature. Another advantage of this construction is that when the vanes 152 become worn, replacement is a simple matter since it is merely necessary to remove the tubular body portion 116 of the housing 112 and to substitute a replacement body portion having new vanes 152 secured thereto through an intervening new annulus 154.

The cam 132 is shown as provided with two diametrically-opposed lobes 156 which alternately increase and decrease the volumes of the spaces 158 between the vanes 152, as the cam rotates, to provide the pumping action characteristic of a pump of this type. With the two lobes 156 shown, the volume of each intervane space 158 is alternately increased and decreased twice during each cam revolution. However, it will be understood that the number of pumping cycles per cam revolution may be increased or decreased through the use of a cam having more lobes, or one lobe.

The cam 132 acts as an inlet valve means for delivering the fluid to be pumped to the intervane spaces 158 as the volumes thereof are increased in response to cam rota' tion. More particularly, the cam 132 is provided therein with inlet passage means 160 having an axial inlet end 162 formed in the end wall 144 of the `cam and centrally located on the axis of rotation thereof. The inlet passage means 169 includes a cylindrical cent-ral portion 164 one end of which defines the axial inlet end 162. The inlet passage means 160 includes outlet branches 165 respectively terminating in outlet ends 166 in the peripheral wall 146 of the cam 132, such outlet ends being -bifurcated by radial partitions 168 to prevent damage to the vanes 152 by the edges of the outlet ends of the inlet passage means.

The outlet ends 166 of the inlet passage means 160 are so located circumferentially of the peripheral wall 146 of the cam 132 that they deliver the fluid to be pumped to those intervane spaces 158 the volumes of which are being increased as the cam rotates in the direction of the arrow 170, FIG. 6. This action is characteristic of pumps of this type so that a further description is not necessary.

The iiuid to be pumped is introduced into the axial inlet end 162 of the inlet passage means 160 through an axial inlet port 176 in the end portion 118 of the housing 112. An O-ring 178 is carried by the e-nd portion 118 and encircles the axial inlet port 176, such O-ring engaging the end wall 144 of the cam 132 around the axial inlet end 162 of the inlet passage means 160 to provide a fluid tight seal.

The annular flange 148, in addition to closing the open end 122 of the pumping chamber 120, also serves as an outlet valve means for receiving the pumped fluid from those intervane spaces 158 the volumes of which are being decreased by the cam 132. More particularly, the annular ange 14-8 may be regarded as constituting -an outlet valve plate, and it is provided, between the peripheral wall 146 of the cam 132 and the peripheral wall of the pumping chamber, i.e., between the peripheral wall 146 of the cam 132 and the elastomeric annulus 154, with two circumferentially extending outlet openings 180 so located circumferentially as to be in communication with the decreasing-volume intervane spaces.

The outlet openings 180 in the outlet valve plate 148 are in constant communication with an annular outlet passage means 182 formed in the end portion 118 of the housing 112 and leading to an outlet port 184 formed therein. The outlet passage means 182, which is located on the opposite side of the outlet valve plate 148 from the pumping chamber 120, encircles the axial inlet port 176 and is sealed with `respect thereto by the O-ring 178. Another O-ring 186, carried by the end portion 118, engages the outlet valve plate 148v Vadjacent its periphery and seals the outer periphery of the annular outlet passage means 182. It will be noted that the side of the outlet valve plate 148 opposite the O-ring 186 engages the elastomeric annulus 154 to seal the outer boundaries of the intervane spaces 158 in a uid ltight manner.

PUMP 210 In the pumps 16 and 110 hereinbefore described, the fluid to be pumped is introduced at ione end only, and the pumped uid is similarly discharged at one end only. Considerably higher rotational speeds can be used by introducing the uid and discharging it at both ends. FIG. 7 shows, semi-diagrammatically, a pump 210 of the invention which accomplishes this.

The pump 210 comprises a housing 212 which includes a tubular body portion 216 closed at its end by closure portions 218. A shaft 226 extends axially through the body and closure portions 216 and 218 of the housing 212 and is supported by suitable lbearings, not shown, and sealed by suitable sealing assemblies 230. The shaft 226 carries a cam 232 which may be generally similar to the cam 132 and which is secured to the shaft by a key 240. The cam 232 differs from the cam 132 in having an outlet valve plate 248 at each end running in an annular groove 250 in the corresponding closure portion 218. The cam 232 engages flexible, elastomeric vanes 252 integral with an elastomeric annulus 254 bonded to the tubular body portion 216. In this respect, the tubular body portion 216 is similar to the tubular body portion 116.

The cam 232 differs further from the cam 132 in that it is provided with an inlet passage means 260 having axial inlet ends 262 at both ends of the cam. The inlet passage means 260 ter-minates in outlet ends 266 in much the same manner as the inlet passage means 160. The closure portions 218 are provided with inlet ports 276 respectively -communicating with the axial inlet ends 262 of the inlet passage means 260 in the cam 232, fluid tight seals around the inlet ports 276 being provided by O- rings 278.

vThe outlet valve plates 248 are provided therein with outlet openings 280 similar to the outlet openings 180 in the outlet valve plate 148. The closure portions 21S of the housing 212 are respectively provided with annular outlet passage means 282 communicating with the `outlet openings 280 `in the respective outlet valve plates 248. The closure portions 218 are also provided with outlet ports 284 `respectively communicating with the two annular outlet passage means 282. O-rings 286 provide fluid tight seals around the two annular outlet passage means 282, such O-rings engaging the outer sides of the two outlet valve plates 248 yadjacent the peripheries thereof. The inner sides of the two outlet valve plates 248 engage the elastomeric annulus 245 in much the same manner as the outlet valve plate 148 engages the elastomeric annulus 154.

As will be apparent from FIG. 7, the pump 210 supplies the fluid to be pumped to the increasing-volume intervane spaces through both ends of the cam 232. Similarly, the pumped fluid is discharged from the decreasingvolume intervane spaces at both ends of the pump 218. Consequently, higher speeds may be used with the cam 232 than with the cam 132.

Although exemplary embodiments of the invention have been disclosed herein for purposes of illustration, it will be understood that various changes, modifications and substitutions may be incorporated in such embodiments without departing from the spirit of the invention as defined by the claims which follow.

I claim:

1. In a rotating-cam vane pump, the combination of:

(a) a housing provided) therein with a cylindrical pumping chamber open at one end;

(b) a cam in and rotatable about the axis of said pumping chamber and having axially spaced end walls and a peripheral wall;

(c) a shaft rotatable relative to said housing about the axis of said pumping chamber and connected to said cam to rotate same;

(d) circumferentially spaced, displaceable vanes carried by said housing and extending inwardly into said pumping chamber and into engagement with said peripheral wall of said cam;

(e) said cam alternately increasing and decreasing the volumes of the spaces between said vanes as it rotates;

(f) inlet passage means in said cam for delivering fluid to be pumped to the intervane spaces as the volumes thereof are increased;

(g) said inlet passage means having an inlet end formed in one of said end walls of said cam, and having an outlet end in said peripheral wall of said cam;

(h) an outlet valve plate on one end of and extending radially outwardly from and rotatable with .said cam;

(i) the periphery of said outlet valve plate closing said open end of said pumping chamber;

(j) an outlet opening in said outlet valve plate radially outwardly from said cam, said outlet opening receiving lluid being pumped from the intervane spaces as the volumes thereof are decreased;

(k) outlet passage means in said housing on the opposite side of said outlet valve plate from said pumping chamber and communicating with said outlet opening in said outlet valve plate;

(l) an inlet port in said housing and communicating with said inlet end of said inlet passage means; and

(m) an outlet port in said housing and communicating with said outlet passage means.

2. In a rotating-cam vane pump, the combination of:

(a) a housing provided therein with a cylindrical pumping chamber open at one end;

(b) a cam in and rotatable about the axis of said pumping chamber and having axially spaced end walls and a peripheral wall;

(c) a shaft Irotatable relative to said housing about the axis of said pumping chamber and connected to said cam to rotate same;

(d) circumferentially spaced, displaceable vanes carried by said housing and extending inwardly into said pumping chamber and into engagement with said peripheral wall of said cam;

(e) said cam alternately increasing and decreasing the volumes of the spaces between said vanes as it rotates;

(f) inlet passage means in said cam for ydelivering fluid to be pumped to the intervane spaces as the volumes thereof are increased;

(g) said inlet passage means having an axial inlet end formed in one of said end walls of said cam and lying on the axis of said pumping chamber, and having an outlet end in said peripheral wall of said cam;

(h) an outlet valve plate on one end of and extending radially outwardly from and rotatable with said cam;

(i) the periphery of said outlet valve plate closing said open end of said pumping chamber;

(j) an outlet opening in said outlet valve plate radially outwardly from said cam, said outlet opening receiving Huid being pumped from the intervane spaces as the volumes thereof are decreased;

(k) outlet passage means in said hou-sing on the opposite side of said outlet valve plate from said pumping chamber and communicating with said outlet opening in said outlet valve plate;

(l) an axial inlet port in said housing and communicating with said axial inlet end of said inlet passage means; and

(m) an outlet port in said housing and communicating with said outlet passage means.

3. In a rotating-cam vane pump, the combination of:

(a) a housing provided therein with a cylindrical pumping chamber open at one end;

(b) a cam in and rotatable about the axis of said pumping chamber and having axially spaced end walls and a peripheral wall;

(c) a shaft rotatable relative to said housing about the axis of said pumping chamber and connected to said cam to rotate same;

(d) circumferentially spaced, displaceable vanes carried by said housing and extending inwardly into said pumping chamber and into engagement with said peripheral wall of said cam;

(e) said cam alternately increasing and decreasing the volumes of the spaces between said vanes as it rotates;

(f) inlet passage means in said cam for delivering fluid to be pumped to the intervane spaces as the Volumes thereof are increased;

(g) said inlet passage means having an axial inlet end formed in one of said end walls of said cam and lying on the axis of said pumping chamber, and having an outlet end in said peripheral wall of said cam;

(h) an axial inlet port in said housing and communieating with said axial inlet end of said inlet passage means;

(i) an outlet valve plate on one end of and extending radially outwardly from and rotatable with said cam;

(j) the periphery of said outlet valve plate closing said open end of said pumping chamber;

(k) an outlet opening in said outlet valve plate radially outwardly from said cam, said outlet opening receiving uid being pumped from the intervane spaces as the volumes thereof are decreased;

(l) annular outlet passage means in said housing on the opposite side of said outlet valve plate from said pumping chamber and encircling said axial inlet port and communicating with said outlet opening in said outlet valve plate; and

(m) an outlet port in said housing and communicating with said outlet passage means.

4. In a roating-cam vane pump, the combination of:

(a) a housing provided therein with a cylindrical pumping chamber open at one end;

(b) a cam in and rotatable about the axis f said pumping chamber and having axially spaced end walls and a peripheral wall;

(c) a shaft rotatable relative to said housing about the axis of said pumping chamber and connected to said cam to rotate same;

(d) circumferentially spaced, displaceable vanes carried by said housing and extending inwardly into said pumping chamber and into engagement with said peripheral wall of said cam;

(e) said cam alternately increasing and decreasing the volumes of the spaces between said vanes as it rotates;

(f) inlet passage means in said cam for delivering lluid to be pumped to the intervane `spaces as the volumes thereof are increased;

(g) said inlet passage means having an axial inlet end formed in one of said end walls of said cam and lying on the axis of said pumping chamber, and having an outlet end in said peripheral wall of said cam;

(h) an axial inlet port in said housing and communicating with said axial inlet end of said inlet passage means;

(i) an outlet valve plate on one end of and extending radially outwardly from and rotatable with said cam;

(j) the periphery of said outlet valve plate closing said open end of said pumping chamber;

(k) an outlet opening in said outlet valve plate radially outwardly from said cam, said outlet opening receiving fluid being pumped from the intervane spaces as the volumes thereof are decreased;

(l) annular outlet passage means in said housing on the opposite side of said outlet valve plate from said pumping chamber and encircling said axial inlet port and communicating with said outlet opening in said outlet valve plate;

(m) an outlet port in said housing and communicating with said outlet passage means; and

(n) said housing including a body portion having `said pumping chamber therein and an end closure portion having said outlet passage means, said inlet port and said outlet port formed therein.

5. ln a rotating-cam vane pump, the combination of:

(a) a housing provided therein with a cylindrical pumping chamber open at one end;

(b) a cam in and rotatable about the axis of said pumping chamber and having axially spaced end walls and a peripheral wall;

(c) a shaft rotatable relative to said housing about the axis of said pumping chamber and connected to said cam to rotate same;

(d) circumferentially spaced, flexible elastomeric vanes carried vby said housing and extending inwardly into said pumping chamber and into engagement with said peripheral wall of said cam;

(e) said cam exing said vanes as it rotates so as to alternately increase and decrease the volumes of the spaces between said vanes;

(f) inlet passage means in said ycam for delivering fluid to be pumped to the intervane spaces as the volumes thereof are increased;

(g) said inlet passage means having an axial inlet end formed in one of said end walls of said cam and lying on the axis of said pumping chamber, and having an outlet end in said peripheral wall of said cam;

(h) an axial inlet port in said housing and com-municating with said axial inlet end of said inlet passage means;

(i) an outlet valve plate on one end of and extending radially outwardly from and rotatable with said cam;

CTI

(j) the periphery of said outlet valve plate closing said open end of said pumping chamber;

(k) an outlet opening in said outlet valve plate radially outwardly from said cam, said outlet opening receiving fluid being pumped from the intervane spaces as the volumes thereof are decreased;

(l) annular outlet passage means in said housing on the opposite side of -said outlet valve plate from said pumping chamber and encircling said axial inlet port and communicating with said outlet opening in said outlet valve plate;

(m) an outlet port in said housing and communicating with said outlet passage means; and

(n) said housing including a body portion having said pumping chamber therein and an end closure portion having said outlet passage means, said inlet port and said outlet port formed therein.

6. In a rotating-cam vane pump, the combination of:

(a) a housing provided therein with a cylindrical pumping chamber open at its ends;

(b) a cam in and rotatable about the axis of said pumping chamber and having axially spaced end walls and a peripheral wall;

(c) a shaft rotatable relative to said housing about the axis of said pumping chamber and connected to said cam to rotate same;

(d) circumferentially spaced, displaceable vanes carried by said housing and extending inwardly into said pumping cham-ber and into engagement with said peripheral wall of said cam;

(e) said cam alternately increasing and decreasing the volumes of the spaces between said vanes as it rotates;

(f) inlet passage means in said cam for delivering fluid to be pumped to the intervane spaces as the volumes thereof are increased;

(g) said inlet passage means having inlet ends respectively formed in said end walls of said cam, and having an outlet end in said peripheral wall of said cam;

(h) two outlet valve plates on the respective ends of and extending radially outwardly from and rotatable with said cam;

(i) the peripheries of said outlet valve plates respectively closing said open ends of said pumping chamber;

(j) outlet openings in said outlet valve plates radially outwardly from said cam, said outlet openings receiving iluid being pumped from the intervane spaces as the volumes thereof a-re decreased;

(k) two outlet passage means in said housing on the opposite sides of said outlet valve plates from said pumping chamber and communicating respectively with said outlet openings in said outlet valve plates;

(l) two inlet ports in said housing and respectively communicating with said inlet ends of said inlet passage means; and

(rn) outlet ports in said housing and respectively communicating with said outlet passage means.

7. In a rotating-cam vane pump, the combination of:

(a) a housing provided therein with a cylindrical pumping chamber open at one end;

(b) a cam in and rotatable about the axis of said pumping chamber and having axially spaced end walls and a peripheral wall;

(c) a shaft rotatable relative to said housing about the axis of said pumping chamber and connected to said cam to rotate same;

(d) circumferentially spaced, flexible, elastomeric vanes carried by said housing and extending inwardly into said pumping chamber and into engagement with said peripheral wall of said cam;

(e) said vanes being formed integrally at their outer ends with an elastomeric annulus within and bonded to said housing;

(f) said cam alternately increasing and decreasing the volumes of the spaces between said vanes as it rotates;

(g) inlet passage means in said cam for delivering uid to be pumped to the intervane spaces as the volumes thereof are increased;

(h) said inlet passage means having an inlet end formed in one of said end walls of said cam, and having an outlet end in said peripheral wall of said cam;

(i) an outlet valve plate on one end of and extending radially outwardly from and rotatable with said cam;

(j) the periphery of said outlet valve plate closing said open end of said pumping chamber;

(k) an outlet opening in said outlet valve plate radially outwardly from said cam, said outlet opening receiving fluid being pumped from the intervane spaces as the volumes thereof are decreased;

1(1) outlet passage means in said housing on the opposite side of said outlet valve plate from said pumping chamber and communicating with said outlet opening in said outlet valve plate;

(m) an inlet port in said housing and communicating 12 with said inlet end of said inlet passage means; and (n) an outlet port in said housing and communicating with said outlet passage means.

References Cited by the Examiner UNITED STATES PATENTS 2,933,046 4/1960 McCray 103-117 2,971,469 2/1961 McLean 103-117 2,976,811 3/1961 Sully 103-117 3,128,707 4/1964 Brundage 103-126 FOREIGN PATENTS 452,757 11/ 1948 Canada.

622,779 6/1927 France. 1,276,001 10/1961 France.

537,215 12/1955 Italy.

DONLEY J. STOCKING, Pri/nary Examiner.

20 SAMUEL LEVINE, MARK NEWMAN, Examiners.

R. M. VARGO, Assistant Examiner. 

1. IN A ROTATING-CAM VANE PUMP, THE COMBINATION OF: (A) A HOUSING PROVIDED THEREIN WITH A CYLINDRICAL PUMPING CHAMBER OPEN AT ONE END; (B) A CAM IN AND ROTATABLE ABOUT THE AXIS OF SAID PUMPING CHAMBER AND HAVING AXIALLY SPACED END WALLS AND A PERIPHERAL WALL; (C) A SHAFT ROTATABLE RELATIVE TO SAID HOUSING ABOUT THE AXIS OF SAID PUMPING CHAMBER AND CONNECTED TO SAID CAM TO ROTATE SAME; (D) CIRCUMFERENTIALLY SPACED, DISPLACEABLE VANES CARRIED BY SAID HOUSING AND EXTENDING INWARDLY INTO SAID PUMPING CHAMBER AND INTO ENGAGEMENT WITH SAID PERIPHERAL WALL OF SAID CAM; (E) SAID CAM ALTERNATELY INCREASING AND DECREASING THE VOLUMES OF THE SPACES BETWEEN SAID VANES AS IT ROTATES; (F) INLET PASSAGE MEANS IN SAID CAM FOR DELIVERING FLUID TO BE PUMPED TO THE INTERVANE SPACES AS THE VOLUMES THEREOF ARE INCREASED; (G) SAID INLET PASSAGE MEANS HAVING AN INLET END FORMED IN ONE OF SAID END WALLS OF SAID CAM, AND HAVING AN OUTLET END IN SAID PERIPHERAL WALL OF SAID CAM; (H) AN OUTLET VALVE PLATE ON ONE END OF AND EXTENDING RADIALLY OUTWARDLY FROM AND ROTATABLE WITH SAID CAM; (I) THE PERIPHERY OF SAID OUTLET VALVE PLATE CLOSING SAID OPEN END OF SAID PUMPING CHAMBER; (J) AN OUTLET OPENING IN SAID OUTLET VALVE PLATE RADIALLY OUTWARDLY FROM SAID CAM, SAID OUTLET OPENING RECEIVING FLUID BEING PUMPED FROM THE INTERVANE SPACES AS THE VOLUMES THEREOF ARE DECREASED; (K) OUTLET PASSAGE MEANS IN SAID HOUSING ON THE OPPOSITE SIDE OF SAID OUTLET VALVE PLATE FROM SAID PUMPING CHAMBER AND COMMUNICATING WITH SAID OUTLET OPENING IN SAID OUTLET VALVE PLATE; (I) AN INLET PORT IN SAID HOUSING AND COMMUNICATING WITH SAID INLET END OF SAID INLET PASSAGE MEANS; AND (M) AN OUTLET PORT IN SAID HOUSING AND COMMUNICATING WITH SAID OUTLET PASSAGE MEANS. 